Structures for use on both land and/or water as security barrier systems have been previously developed. Such structures generally intend to stop intruding objects, and range from thick, solid walls blocking the object's progress to secured areas for disabling the propelling mechanism of the object. These structures commonly exhibit noticeable shortcomings. First, these structures are often cumbersome and time-consuming to install and erect as and where desired. Second, they are difficult, or even impossible, to maintain and/or repair after they have sustained the impact of an intruding object. Third, they are often not adaptable to different needs and conditions.
One solution providing an improved marine barrier is disclosed in U.S. Pat. No. 8,920,075, which is hereby incorporated by reference in its entirety. The marine barrier of the '075 patent includes two continuous pleated rows of first and second respective pluralities of buoyant panels, to form a diamond-shaped barrier. A plurality of hinges elastically connect opposing sides of adjacent panels with an included angle therebetween to form two continuous pleated rows, and the hinges are arranged in first, second, and third substantially parallel rows. A first plurality of impact cables (or an impact net) are attached to opposing ends of the first pleated row of panels and pass through each of the hinges in the first row of hinges. A second plurality of impact cables (or an impact net) are attached to opposing ends of the second pleated row of panels and pass through each of the hinges in the third row of hinges. When the barrier is floating in water and a moving vessel impacts the first or second plurality of impact cables, those impact cables deflect to transfer a force of the impact to one or more of the panels, which in turn engage the water to transfer the force of the impact to the water, to arrest the motion of the vessel. In other words, during an impact the panels are drawn in around the point of impact and engage the water to dissipate the impact force.
The marine barrier of the '075 patent is a vast improvement over previous barriers, but is designed to be a permanent structure, and is designed to have a very high level of effectiveness. Consequently, it may be unnecessarily large, heavy, and/or costly for temporary applications, for deployment in remote areas, or for lower-performance applications that do not require its effectiveness or its built-in redundancies.
In another type of barrier intended to be simpler and lower-cost, a single impact net is strung between central columns in what is referred to as a “single net capture mechanism,” in contrast to the two-net capture mechanism of the '075 patent, which has a set of impact nets or cables attached to each of the front and rear faces of the barrier. A single net capture system is disclosed in U.S. Pat. No. 9,683,342, which is hereby incorporated by reference in its entirety. The marine barrier 200 of the '342 patent, one embodiment of which is shown in FIGS. 8a-b, includes a series of central columns 205 arranged in a line, which support an impact net 210 strung between them. As best seen in FIG. 8b, the central substantially vertical columns 205 are joined to each other and supported in the water by frames, each having a lower horizontal leg 220 attached to a lower portion of the column 205 and a diagonal strut 225 also attached to the column 205. Each leg includes a float 230. The legs 220 and floats 230 are arranged such that a distal end of each of the legs 220 is attachable to a distal end of a corresponding leg 220 of an adjacent column 205 to form a series of diamond-shaped supports between the columns 205, to support the columns 205 and the impact net 210 when the barrier 200 is floating in a body of water. The combination of a column 205 and four frames 215 is referred to hereinafter as a “column module.”
When the barrier 200 is floating in the body of water and a moving vessel 235 impacts the impact net 210, the impact net 210 deflects to transfer a force of the impact to one or more of the column modules (see arrows L), which in turn engage the water to transfer the force of the impact to the water, to arrest the motion of the vessel 235. The barrier 200 can be folded for portability such that the legs 220 are substantially parallel to each other, because the legs 220, struts 225, and columns 205 are joined to each other via elastic hinges 255, 265.
Although the single net barrier of the '342 patent is lighter and more easily portable than previous barriers, its folding legs and struts add cost, complexity, and size when folded, while lowering the system's overall strength. Additionally, its floats are on each of its horizontal legs (four legs for each column module), creating a large water plane area, which tends to make the system unstable in large wave events.
There exists a need for an effective marine barrier that is low cost, simple, and easily portable.